The present invention relates to making electronic documents secure, and more particularly it relates to providing secure access to sensitive text data by means of a trusted processor unit.
In everyday life or in a professional context, for example, it frequently happens that documents are involved in which the content is sensitive and therefore needs a certain level of security. This may apply for example to a confidential document such as a contract containing sensitive information (the names of parties, sums of money, special clauses, . . . ) to which the parties involved desire to protect access.
FIG. 1 shows an example of a user 4 using a terminal 2 to access an electronic document 6 (e.g. of Word™ or PDF™ type) contained in a file F1. Consideration is given in this example to such a document 6 containing conventional text data 8 that does not need any particular protection, and “sensitive” text data 10 that the creator of the document considers to be sensitive.
In known manner, the level of security to which the document 6 benefits while it is being viewed by the user 4 depends in particular on the degree of trust that can be given to the terminal 2 in use. Very often terminals (computers, tablets, etc.) are exposed to security risks, in particular to risks of intrusion or of infections by malware (viruses, monitoring devices, . . . ), that are difficult to control. If the terminal 2 is not a trusted terminal, then access to the document 6 and most particularly to the sensitive data 10 via the terminal 2 thus presents risks in terms of security.
It is not always possible for the user 4 to know the level of trust that can be given to the terminal 2 in use, nor the level of trust that is required to be able to access the data in the text 8 in complete security. It is also not always possible for the user 4 to know whether the document 6 to which he/she seeks to gain access contains information that is sensitive, and if so where that information appears in the document 6 in question.
At present there is no solution that makes it possible to respond effectively to these problems. There already exist various encryption solutions that make it possible for sensitive electronic documents to be protected by being encrypted. Nevertheless, such solutions are often not ergonomic for a user and they do not always provide a satisfactory level of security.
There thus exists a need for a solution that makes it possible to secure access to sensitive text data in order in particular to reduce any risk of non-authorized access to the sensitive data in question. In particular, it is necessary to provide more effective protection for accessing sensitive text data (e.g. contained in an electronic document) even while using a terminal that benefits from a level of trust or security that is poor.